[ganeumann]

You are free to ignore or block their ads. Sites may complain about blocking, but (almost?) none prevent it. But the sites are also free to put ads on their sites, why wouldn't they be, and how do you feel that this is "beyond the pale"? The people who run those sites are just trying to make a living in the same way that most popular media has tried to make a living for the past century.

But actively trying to disrupt how they make a living goes beyond that. Imagine a museum that has a donation box but where you can go in for free if you want. You don't have to donate, but gumming up the slot so no one else can donate either goes beyond being not thinking the museum is worth paying for (although, for some reason, you're in it) to not thinking it should be in business at all.

By arguing that instead of taking donations they should just charge admission, you're just rationalizing bad behavior.

[doki_pen]

It's more like a donation box that automatically takes money out of your pocket unless you are vigilant, with most patrons not noticing that it took their money. The analogy sort of fails because it's not a zero sum gain. You could actually argue that targeted ads are a benefit to users.